The object this study is to preserve sea-water acclimatized chlorella with condensation of 1 x 10^8 cells/ml as living chlorella. after winter sleepnized treatment to change mushy, gelatlniform and dried powdered conditions.As speclmens in the experiments, optimal temperature 35ﾟC of high temperature straln(Chlorella sp)and optimal temperature 25ﾟC of middle temperature strain were used. During the treatment for dormancy, the culture temperature was gradually decreased to at 5ﾟC and 0ﾟC for 1 week.Obtained results were follows.(1)In the treatment for dormancy, optimal temperatures for high temperature strain and middle temperature strain were 5ﾟC and 0ﾟC respectively.Among preservations for 1 month of musy, gelatiniform and dried powdered conditions under salinity of 50%, 35% and 70%, those chlorella under the treatment for dormancy showed good propagation atter their restoration.